1917/1920 Double Stamp LUGER

My Luger is a DWM, designated as P.S. 3 on the grip and is in 85% condition. It is from the Sachen Police School (District of Ansbach) in Bavaria. It was originally manufactured in Berlin-Charlotteberg in 1917. Refabricated in 1920. It has the serial # 1000 on all parts including the mag which is wood based. Can someone help with an approximate value? Thank you